Brake band



Jfw. "rAYTrER BRAKE BAND May 19,1931.`

original Filed Nov.; 3. 192e 3, W f- M w 2Q 2 Q Patented vMay 19,1931

UNITED slfgivrrss PATENT oFFlcE l .Tomi w. Tanna, or@modulators/Assiettes 'To LEWIS DIFFERENTIAL conramnor emesso, mentors,a conroaarroN or rumors f Baaxnnam f Original applicationVledlliov'ember 3,1926, Serial Io: 145,970. Divided and this applicationmed .Tune

' 10, 1,929. Serial I0. $69,842. y

My invention relates to brake mechanism and has among itsobjects theproduction. of

a device of the kind described which is simple, compact, convenient,durable, eicient and satisfactory for use wherever found applicable. Y

This application is a division of my pending apphcation, Serial No.145,970, liled November 3, 1926 for brake mechanisms.y

The invention is particularly adapted to vbe embodied in mechanisms ofthe kind comprising brake drumsand brake bands, or the equivalent, aparticular object being to provide an improved brake band forfriction-15 ally engaging the brake drum SOthat the braking eii'ect is appliedsmoothly and effectively without chatteringv and without subjecting anyparticular portion of the brake band to more wear than another portionthereof. Y i,

More particularly, it has as an objectthe 'production of a brake bandwhich will contract or expand during the braking action in such mannerthat substantially all lof the working surface of the friction of theband willuniformly engage the brake drum as distin 'shed from thosebands wherein the end portions engage the brake drum before the centralportiongof the friction lining comes intoengagement therewith.

Many other objects and advantages of the construction herein shown anddescribed will be obvious to those skilled in the'art fromthe disclosureherein given.

i To this end my inventionlconsists in the novel construction,arrangement and oo mbination of parts herein shown and described, andmore particularly pointed out 1n the claims. y Inthe drawings, whereinlike reference characters indicate like or corresponding t parts: v

Fig. 1. is a view in elevation of my 1mproved band and certainassociated parts of the braking mechanism; A

Fig. 2 is a view vin elevation of the band disassociated from thefriction .lining and other parts of the brake mechanism and; Fig: 3 is asectional view through theband taken substantially online 3-4-3 of Fig.f2;

or pivoted by 32 and 33, respectively, movable alon a rod 35 which ispreferably provided wit right 100 Referring to 1 and/2 wherein I haveshown one'form ofthe invention embodied in braking mechanismparticularly adapted to be employed in connection with automobiles,

and thelike, 11 designates a shaft .to be u braked as, .for example, thepropeller shaft of an automobile, this being operatively connected bysuitable means not shown to a driven and driving mechanism. Theparticular'shaft 11 shown forms no p`art of the w present invention andneed not be described in detail. Constrained kto rotate. with the shaftor afsection secured thereto is a brake drum 17 `formed with kacylindrical surface yor friction face 18 which is engageable by a 65friction lining 19 the 19 'being car# ried by a flexible arcuate brakeband 20. In

this instance, the friction lining 19 is secured in any suitable mannerto the inner surface of the brake band 20 and the outer surface 70 ofthe b rake band is eccentrically formed with respect to the innersurface. My invention is illustrated in connection with an externalcontracting type of brake although in principle it is equally effectiveand applicable to internal expanding types of brakes. Thus, the thickestportion of the brake vbend 2O is preferably at a point substantia'lymidwaybetween the ends thereof and is designated by the referencecharacter 22. Seso cured to the portion 22 of the brake band 20 andprojecting therefrom is a pin 24 which rides in a slot 25 formed in abrake member 26 which is rigidly secured to the transmission housing brother support by any suitable means such as, -for instance, bolts 27, orthe equivalent. The slot 25 is arranged circumferentially with 3respectto the brake band 17 so that the brake band 20 may be displacedcircumferentially of the brake 9 l drum but cannot move laterally withrespect thereto. While the band described may be used associated withany suitable brake mechanism, I have illustrated the same embodied in. amechanism whichv may be deg5 scribed as follows: I

The ends of the brake band 20 are hinged pins 30 and 31 to members tiveto the members.

and left hand yscrew-threads 36 and 37, res ctively. The members 32 and33Aare rovided with lugs 38 and 39, respectively, w ich engage nuts 40and 41, respectively, and prevent angular displacement of the nuts rela-It will be noted that the nuts 40 and 41 engage the screw-threads 36 and37, respectively. Obviously, if the rod 35 is rotated in one direction,the nuts 40 and 41 will move toward each other and cause the members 32and 33 to bring the ends Vof the brake band toward each other mso thatthe friction lining 19 will engage the face 18 of the brake drum 17. Ifthe rody is rotated in the opposite -direction, the` nuts and 41willmove away from eachother so that the brake band 20 may expand y andbring the friction lining 19 out of effective engagement with the brakedrum. It is understood, of course, that the brake band 20 is preferablyresilient as well as flexible so that it normally assumes a form whereinit will not cause the brake lining 19 to effectively engage the brakedrum.

The other parts of `the brake mechanism associated with the band neednot be de-l scribed with further detailhere'in as this mobile wishes toapply al] braking action to the shaft, itis obvious that if the drivermanipulates suitable mechanism to angularly displace the rod 35 so thatthe nuts 40 and 41 will move toward each other, the ends of the brakeband 20 will be moved toward each other and the lining 19 will engagethe brake drum 17 and retard rotation thereof. Be-

cause of the fact 'that the brake band 20y diminishes in thickness fromits central portion to its ends or varies in-its flexibility between theends, -the brake band will be unformly contracted in such manner thatsubstantially all of the inner, surface of the friction lining 19, willimmediatelyengage the brake drum. This distinguishes from braking aparatus wherein brake bands are provi ed ness throughout their lengths,-forl in such construction, the brake bands tend to bend at first atpoints disposed substantially midway between their ends., these pointsbeing sill-Elected to the greatest leverage. JWhen.

b e bands first bend at the points located substantially midway betweentheir ends and not contract uniformly, the pdrtions of the frictionlining disposed adjacent the ends of the brake bands engage the brakedrum before the central portions of the friction 1ining comes intoengagement therewith. `Obviously, the end portions of the frictionlinration of the braking mechanism is aving substantially the samethick-l ing will be subjectedA to 'more wear than the central portionsthereof. Then, because the brake drum is not engaged by substantiallythe entire friction lining in each instance,

4the braking action is not eflicient. In apparatus embodying the presentinvention,

the friction limn engages the brake drum in such manner t at the-brakingaction is,

smooth. v

The construction kof the members 32 and 33 i`s particularly advantageousin that .these members vcan not pivot or rock around the -longitudinalaxes of the pins 30 and 31 toward. each other -as the lugs riding uponthe anti-friction rollers 47 prevent such movement thereof.4 Itfwill bereadily understood that if the upper portions of the members 32 and 33could move toward each other without like movement of the lower portionsthereof, the ends of the brake band 20 would` be moved inwardly towardthe brake drum 17 before the portion 22 thereof would bring yment withthe drum.

Having thus described my invention, it is' obvious thatvariousimmaterial modifications may be made in the same withoutdeparting to the exact form, construction, arrangement and combinationof parts herein shown and described or uses mentioned.

,What clai'm as new and desire to secure by Letters Patent is 1. Aflexible brake band of substantially rectangular cross section whichdiminishes in cross-sectional area from its central portion to the endsthereof.

2. A flexible brake band which diminishes in its radial cross-sectionaldimension from substantially'the central portion-thereof to the endsthereof. e

3. A brake band of the kind described consisting of a split resilientring, the yring being constructed to p rovidefor relatively greaterflexibility adjacent the ends than at any point intermediate. its ends.`l

4, A 'brake band of the kind described consisting` of a strip ofresilient material varying substantiall uhiforml in its flexibilityintermediate its ends, w ereby u n bringing the ends ofthe ring toethfer t e same contracts substantially uni ormly throughout its length.

5. A brakeband of the kind described con-- andssubstantially uniformlythroughout its ength when the ends are brought together or spring outardly.

6. In. a bra e, a drum, a substantially circular yielding banddiminishing in thickness from substantially the mid-point toward' itsadjacent ends, friction lining carried by the shoe for engagement withthe drum, and means relatively moving said adjacent ends of the shoe.

7. In a brake, a drum, a substantially circular yielding metallic shoedlmmlshmg 1n thickness from substantially the mid-point toward itsadjacent ends whereby the shoe will move concentrically with the drumthroughout its length, friction linin of substantially uniform thicknesscarrie bythe shoe for engagement with the drum, and brake applying meansacting on the said adjacent ends of the shoe. f

8. Ina brake, `a drum, a yielding metallic shoe substantially uniformlydiminishing in thickness toward one end thereof whereby the shoe isinduced to move concentrically (with the drum, friction lining ofsubstantially uniform thiclmess carried b the shoe for engagement withthe drum, an brake applying means acting on said shoe end.

9. In a brake, a drum, a yielding metallic shoe substantially circularin form and substantially uniformly diminishing in its radialcross-sectional dimension towards adjacent ends thereof whereby the shoeis in-I duced to move concentrically with the drum, frictionv lining ofsubstantially uniform thickness carried by the shoe for engagement withthe drum, and brake applying means acting on said adjacent shoe ends.

l0. In a brake, a drum, a yielding metallic one-piece shoe substantiallycircular inform and substantially uniformly diminishing in its radialcross-sectional dimension towards adjacent ends thereof from a pointsubstan tially ymidway of its circumferential length whereby the shoe isinduced to move concentrically with the drum, friction lining ofsubstantially uniform thickness carried by the shoe for engagement withthe drum, and Y brake applying means acting on said adja-v cent shoeends. f

In witness whereof, I hereunto subscribeI my name this 5th da of JuneA..D., 1929. JyOHN W. TATTER.

